Sorghum x sudangrass is an important forage crop in semi-arid regions due to its high biomass potential and efficient water use. Improving irrigation and nitrogen management is essential to sustain productivity under increasing water limitations. This study evaluated the effects of different irrigation levels and nitrogen doses on the growth, physiological responses, and forage traits of sorghum x sudangrass. Four irrigation levels (25, 50, 75, and 100% of full irrigation) and three nitrogen doses (50, 100, and 150 kg ha-1) were tested with three replications. Irrigation, nitrogen, and their interaction significantly affected plant performance. Plant height ranged from 227.3 cm under 25% irrigation with 50 kg N ha-1 to 313.6 cm under 75% irrigation with 100 kg N ha-1. Fresh forage yield varied between 23.5 and 66.7 t ha-1, while dry biomass ranged from 5.01 to 16.77 t ha-1. Physiological parameters responded positively to increasing inputs; the highest SPAD value (45.36) occurred at 75% irrigation with 100 kg N ha-1. LAI and NDVI reached their maximum under full irrigation with 100-150 kg N ha-1. Forage quality traits also responded to the treatments. ADF and NDF increased slightly with higher inputs, while crude protein yield ranged from 296 to 1191 kg ha-1. Overall, 75% irrigation combined with 100 kg N ha-1 produced yields and protein levels comparable to full irrigation with 150 kg N ha-1, indicating a more resource-efficient and sustainable management strategy. Incorporating drought-tolerant and resource-efficient forage species may further improve system resilience under Mediterranean water-limited conditions.